Migration is an issue fervently debated in various scientific fields (history, sociology, political science, security studies, etc.). Postmodern literature on migration goes beyond hundreds of titles, monographs and articles. Discourses on public migration policies and sometimes policies themselves all too often tend to be based on seemingly trivial correlations, but which have no significant empirical basis. The reality is much less simple and requires a nuanced analysis to interpret it accurately. The emotions and attention aroused in the EU and US public debates on migration issues reveal an identity crisis and only widen the gap between potential evidence-based long-term policies and short-term migrant policies. The article aims to analyse, from a theoretical perspective, the content of the migration phenomenon in the contemporary globalized society, focusing on a series of legal elements, without ignoring the social and economic implications of the phenomenon.